denmead



(No Model.) 1 2 SheetS -Sheet 1. J. W. DENMEAD & R. L. MQALLISTER.

ROTARY ENGINE.

No. 346,029. Patent d July 20, 1886 jzmazazzzm -vzzzl'sr (No Model.) 1 V2 Sheets-Sheet 2. J. W. DENMEAD & R. L. MOALLISTER.

' ROTARY ENGINE. No. 346,029. I Patented July 20, 18 86..

QEW

. flit} N, PETERS, Phnlobkhonphu. Wahingtcn. D. C.

UNITED STATES PATENT QEEicE.

JOHN IV. DENMEAD AND RANDALL L. MGALLISTER, OF AKRON, OHIO, ASSIGNORS OFONE-THIRD TO JAMES OHRISTY, JR, OF SAME PLACE.

ROTARY ENGINE.

SPECIFICATION forming part of Letters Patent No. 346,029, dated July 20,1886.

Application filed February 12, 1886. Serial No. 191,734. (No mode To aZZwhom it may concern:

Be it known that we, JOHN W. DENMEAD and RANDALL L. MoALLIsTER, citizensof the United States, and residents of the city of Akron, in the countyof Summit and State of Ohio, have invented a new and useful Improvementin Rotary Engines, of which the following is a specification.

Our invention has relation to that class of rotary engines in which acylinder, constituting the piston, is mounted eccentrically upon a shaftjournaled centrally within a hollow cylinder, and a movable partitionfollows the face of the piston and closes, between the steam and exhaustports, the space between the piston and the interior of thesteam-cylinder.

The objects of our invention are to avoid friction of the partition, torender it steambalanced, to facilitate the reversing of theengine, andto provide an automatic packing for the piston.

Our invention consists in the devices illustrated in the accompanyingdrawings, as hereinafter described, and specifically claimed.

In the accompanying drawings, Figure 1 is a side elevation; Fig. 2, asection of Fig. 1 at line a: m,- Fig. 3, an elevation of the valve; Fig.4, a transverse section of cylindrical piston, showing automaticpacking; Fig. 5, a plan of Fig. 4., and Fig. 6 a side-elevation ofanother form of piston.

The case consists of a hollow cylinder, A, united with and opening intoan intersecting cylinder, A, the axes of said cylinders being parallel,and their ends closed by suitable heads.

Centrally within. the cylinder A is journaled the shaft 1), upon whichis mounted, eccentrically, the piston 13, the ends of which meet andform a joint with the heads of the case A, and the face of whichfarthest from the shaft Z) meets and forms a joint with the inner faceof the cylinder A.

\Vithin the cylinder A is centrally j ournaled the shaft II, on which isloosely mounted the valve 0, which consists of a semicircular hollowcylinder, which fits within the cylinder A, the lower side being asegment of a cylinder of like diameter with the cylinder A. In each sideof this valve are ports, E F, of like size and relative situation.

\Vithin the valve 0 is an arm, I, keyed to the shaft H, from either sideof which project coiled springs 73 i, which connect with and press uponthe inner face of the lower side of the valve 0. This arm I maybe rockedin either direction by a lever, I, attached, outside of the head, to theshaft II, and retained in any position by the notched segment K. A port,G, through the head, permits the entrance of steam within the valve 0,and an exhaust-port, D, allows its escape after it has caused arevolution of the piston B.

In operation the arm I, being thrown to one side and held by the leverI, compresses the spring i in one direction and releases the pressure ofthe otherspring, i, thereby forcing the angular edge of the valve onthat side against the face of the piston 13, forming a joint therewith.Steam is then introduced through the port G into the inside of the valve0, and thence, so soon as the valve rocks far enough to open the port E,enters the cylinder A between the point where the piston touches itsinternal face and the valve 0. A revolution of thepiston is therebycaused, the edge of the valve 0, following its motion, opens the port Ewide, and afterward gradually closes it, while the revolution of thepiston opens the port D and allows the steam to escape.

To impart momentum to the piston O for the purpose of carrying it pastthe deadcenter, a pulley, J, is fastened to the shaft 1); butin use wepreferably couple two engines on the same shaft, with their dead-pointsopposite. The valve 0, mounted loosely on the shaft II, rocks freelywith slight motion and a minimum of friction, and is perfectly steam-balanced, as

the pressure is equal on every part except the I port E, which isbalanced by the loss of pressure through the port F.

To reverse the engine, the lever I is thrown in an opposite direction,thereby forcing down the opposite edge of the valve 0 against the pistonand permitting steam to enter through the port F.

To insure a tight joint between the piston and cylinder, a shallowrecess is cut or cast across its face, one end of which is at the pointfarthest from the shaft 2), in which recess is attached by one edge apiece of sheet metal, L, Figs. 3, 4, 5, arranged to spring outward by Tofacilitate the operation of engines which run constantly in onedirection, either by causing them to cut off earlier or exhaust sooneror relatively more rapidly, the section of the piston may be changedfrom a circle to other forms, as shown in Fig. 6.

Having thus described our invention, we clai1n 1. The combination, in arotary engine the case whereof consists of two parallel intersectinghollow cylinders, with heads on either end, of a cylindrical pistonmounted eccentrically on a shaft journaled centrally in one of saidcylinders,with a hollow valve,crescent-shaped in cross-section, restingin the ot-her cylinder loosely mounted on a shaft journaled centrallytherein, having like ports on opposite sides through its convex face,and provided with devices, such substantially as shown, by which it isrocked to and retained at either side, subisitantially as shown, and forthe purpose speci- 2. In combination with the cylindrical piston B,mounted eccentrically on the shaft 1) in the cylinder A, thecrescent-shaped valve 0, surrounding the steam-port G, mounted on theshaft H in the cylinder A, provided with ports E F, arm I, springs 11t", and lever I, all constructed and arranged substantially as shown,and for the purpose specified.

8. The combination, in a rotary engine with a revolving eccentricpiston, of a metallic sheet connected at one edge with the piston andhaving the other pressed constantly against the inner face of thecylinder in which said piston revolves, substantially as and for thepurpose hereinbefore set forth.

In testimony that we claim the foregoing, we have hereunto set ourhands, this 23d day of January, A. D. 1886.

JOHN \V. DENMEAD. RANDALL L. MOALLISTER.

\Vitnesses:

O. P. HUMPHREY, E. W. STUART.

